Actually, that might be the way to go, if you cant get this one up and running with that engine, pop off thje bottom 1/2 of it's crank case (for the serial) and fit that to the engine on the VC-160 MKII you have down at the coast.
The MKII & MKIII Series 70 Engines had very few differences, mostly just the float bowl on the carby, so make sure you use the carby that is currently on the Sports, and the rest of the engine can come from the VC-160 MKII.